/// <summary>
/// Enum for easy indexing and checking if a course is of a certain kind
/// </summary>
public enum ThemeIndex
{
    SIGN_ALPHABET,
    SIGN_BASICS,
    SIGN_CLOTHING,
    SIGN_ANIMALS,
    SIGN_FOOD,
    SIGN_HOBBIES,
    SIGN_HOUSE,
    SIGN_FAMILY,
    SPELLING_GEOGRAPY,
    SPELLING_BUILDINGS,
    SPELLING_SPORTS,
    SPELLING_BASICS,
    SPELLING_HOBBIES,
    SPELLING_PEOPLE,
    SPELLING_FRUIT,
    SPELLING_VEGGIES,
    SPELLING_WILD,
    SPELLING_FARM
}